feat($compile): set preAssignBindingsEnabled to false by default

src/ng/compile.js

@@ -1379,7 +1379,7 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
    *
    * The default value is true in Angular 1.5.x but will switch to false in Angular 1.6.x.
    */
-  var preAssignBindingsEnabled = true;
+  var preAssignBindingsEnabled = false;
   this.preAssignBindingsEnabled = function(enabled) {
     if (isDefined(enabled)) {
       preAssignBindingsEnabled = enabled;

test/ng/compileSpec.js

@@ -171,7 +171,9 @@ describe('$compile', function() {
 
     it('should allow preAssignBindingsEnabled to be configured', function() {
       module(function($compileProvider) {
-        expect($compileProvider.preAssignBindingsEnabled()).toBe(true); // the default
+        expect($compileProvider.preAssignBindingsEnabled()).toBe(false); // the default
+        $compileProvider.preAssignBindingsEnabled(true);
+        expect($compileProvider.preAssignBindingsEnabled()).toBe(true);
         $compileProvider.preAssignBindingsEnabled(false);
         expect($compileProvider.preAssignBindingsEnabled()).toBe(false);
       });